Check out this super-smart marine mammal.

Sam learns about an invasive species called the lionfish.

Get to know the Atlantic goliath grouper.

Sam dives deep to discover Shipwreck Reef, where shipwrecks have transformed into an artificial reef system that helps the habitat. Find out why the reef exists in this episode of "What Sam Sees."

More than 400 shark species live in oceans around the world. Find out how sharks help keep marine ecosystems healthy.

Coral is important to marine ecosystems. Learn more about these animals (yep, coral are animals!) through the Sam Cam.

Sam visits a rescue hospital for injured sea turtles. Learn more about these amazing creatures and the people who help them in this total turtle takeover episode of "What Sam Sees."

The sand tilefish can change colors and move rocks across the ocean floor. Find out more about the tricky fish in this episode of "What Sam Sees."

Sam meets a fish that looks like a balloon with a spiky attitude. Swim with Sam in the National Aquarium’s Atlantic Coral Reef in Baltimore, Maryland, to learn more about one of the biggest puffer fish.

Sam hangs out on the bottom of the ocean floor while on the search for a fish with fins that look like wings.

Meet the queen of the ocean on this week’s episode of "What Sam Sees!" We’ll gear up and dive down deep to learn more about this fish and what makes it so extraordinary.

Sam comes face-to-face with a bonnethead shark while diving at the National Aquarium in Baltimore, Maryland. Learn about how sharks of all sizes make a difference in their habitats in this episode of "What Sam Sees."

Follow Sam on a dive at the National Aquarium in Baltimore, Maryland, to learn cool facts about eels. This episode of "What Sam Sees" features the mighty moray, which swims by twisting and turning its superlong body.